I've been noticing something a tad strange on my computer when trying out the Private Browser option that came with Extreme Security (in Firefox).

Sometimes (and I'm not sure what the trigger point is), instead of typing the character I want, a keypress will produce a random character. I see this mainly in the "Save As" dialog - that is as close to a trigger point as I've seen.

However, if I keep pressing the key, it becomes apparent that the characters are being produced in some kind of strange order. It's not the ASCII order, but it's almost the order on the keyboard

For Example. I just started a new Private Browser session, then tried to "Save As" the first image I saw (the Google logo in this case). I hit the "s" key and got a [ character, I kept hitting "s" and got the following: (the ";;;;;;;;;" is where I held down the key experimentally):
[]asdfghjkl;;;;;;;;;;'`\zxcvbnm,./-+\1234567890-=qwertyuiop[]asdfghjkl;'`\zxcvbnm,./-+\1234567890-=qwerty

Anyone else ever seen anything like that?

I've tried using a different keyboard with no change and also tried unplugging the one I have then plugging it back in again.